Infiniti Q45 Throttle Body [Merged 4-8]

[SilverJester]

first off, I am posting in this forum because this is where I found part of my answer...but please move if it's in the wrong place.


I have a 2g which means I have 4 wires going to the TPS. the q45 tps has one pig tail w/ 3 wires and a short harnes w/ 3 wires. So far what I've been able to find is the the short harness is for the actual TPS and the pigtail is for the "idle validation circuit". I'm not sure what that means but I found it on some supra forums. I know that the difference between the 1g and 2g tps is that the the 4th wire (which ells the ecu if the throttle is closed) is seperate on a 1g. Could this be the same thing as "idle validation"?

So far this is the info I have come across as far as wired and what they are for:

q45 tps harness (not the pigtail):
-Red is the 5 volt input wire
-White is the TPS signal wire
-Black is the sensor return wire

2g tps harness:
1 - Green/Yellow (+5v Sensor Power)
2 - Brown/Red (TPS output voltage)
3 - Yellow/Red (IPS switch)
4 - Black (Ground)

Ok so I'm still a little confused on what wires to connect so if anyone has experience or more info t add I would appreciate it.

 

[Boosted98gsx]

Or you can ghetto machine a DSM IAC valve to be universal, as I have.

 

[95eclipser]

It has an integral FIAV and when properly adjusted the car will idle down to the oem idle speed of 750 without any problems.

Hal, have you installed a decent amount of q45 tb? How would i go about setting up the FIAV properly on the q45?

FYI this is my first q45 tb so bare with me. I am trying to get my car started after 4 years.

Drew

 

[Hal]

Here are my instructions that I posted back in 2009, it assumes a DSMLink setup but the mechanical aspects are the same, regardless of EMS

As delivered, it'll need a couple of turns in on the phillips head screw to get the car to start, catch, and run on it's own.

---

All three screws work in unison.

The phillips head actually sets the cold (fast idle), the upper is the fast idle let off, and the lower is the warm idle.

Here's how I do it:

Run the car to normal operating temp.

Calibrate TPS to get a raw of 30.

Now, with the car cold, set the upper screw 1/2 way out and adjust the phillips screw to give a TPS raw of 32

From this point it's a matter of adjusting the phillips screw to give you the correct cold idle (say 1200), the upper screw to decrease the idle as it warms up and the lower screw to give the proper warm idle.

Make sure the idle speed setting in the client is as close as possible to the actual warm idle speed.

Once you get the idle speeds and let off point where you want them, then revisit the tps calibration.

 

[Boosted98gsx]

^^ obviously for the above you'll need to hook up coolant lines to the throttle body's cold idle system (it doesn't matter the direction of flow).

 

[95eclipser]

^^ obviously for the above you'll need to hook up coolant lines to the throttle body's cold idle system (it doesn't matter the direction of flow).

Is this absolutely necessary? I have eliminated a lot of these extra coolant lines.

You must be logged in to view this image or video.

 

[Boosted98gsx]

Is this and absolute necessary? I have eliminated a lot of these extra coolant lines.

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How is the fast idle going to work if it mechanically cannot tell if the engine is warm?

 

[95eclipser]

How is the fast idle going to work if it mechanically cannot tell if the engine is warm?

It might have been a dumb response. But i was on a assumption/hope my AEM standalone would be able to simulate this response somehow.

Hopes and dreams i guess.

 

[Hal]

Short of using timing to control the rpm, you need to move the butterfly and that won't happen electronically with this body.

 

[Boosted98gsx]

Short of using timing to control the rpm, you need to move the butterfly and that won't happen electronically with this body.

Thermo electrics controlled to imitate engine temp?

 

[2slow4utsi]

Thermo electrics controlled to imitate engine temp?

Shut up.

 

[DSM_love_GST]

so which ones can we delete? I am in the middle of having mine done, but I dont know what to delete. I want to delete the vacuum lines. can someone do a write up for this on a 2g?
I need to know what lines I wan weld shut and what I cant.

 

[DSM_love_GST]

Anyone?

 

[Blurred Talon]

Here are my instructions that I posted back in 2009, it assumes a DSMLink setup but the mechanical aspects are the same, regardless of EMS

As delivered, it'll need a couple of turns in on the phillips head screw to get the car to start, catch, and run on it's own.

---

All three screws work in unison.

The phillips head actually sets the cold (fast idle), the upper is the fast idle let off, and the lower is the warm idle.

Here's how I do it:

Run the car to normal operating temp.

Calibrate TPS to get a raw of 30.

Now, with the car cold, set the upper screw 1/2 way out and adjust the phillips screw to give a TPS raw of 32

From this point it's a matter of adjusting the phillips screw to give you the correct cold idle (say 1200), the upper screw to decrease the idle as it warms up and the lower screw to give the proper warm idle.

Make sure the idle speed setting in the client is as close as possible to the actual warm idle speed.

Once you get the idle speeds and let off point where you want them, then revisit the tps calibration.

So will this allow the car to idle correctly from a cold start?
I ask because my car is a DD in the spring/summer and I don't want to bugger around with it trying to get it to idle every day.

 

[Blurred Talon]

I just got my Q45 TB.
There's 2 connectors on the Q45 TPS, I use the longer one correct?
Also, the bolts that came with it (OEM Nissan ones) will they fit my JMF Manifold?

Lastly has anyone pulled the stock FIAV nipples and replaced them with bigger ones? Our cars use bigger hoses then the Nissan.

 

[Blurred Talon]

Gonna try getting an answer here before making a new thread.
Since my car is far away from me, I'm wondering what is needed to bolt a short route FMIC up to the Q45?

 

[ba109296]

The stock nipples on the q45 can be pulled and the hole tapped for whatever size thread you need. Then use whatever adapter you want to make your lines.

 

[ba109296]

The stock nipples on the q45 can be pulled and the hole tapped for whatever size thread you need. Then use whatever adapter you want to make your lines.

 

[4g63t]

Ok for future reference if anyone needs a cheap replacement on the q45 TPS. I had one part of the carbon wiper come off inside the tps, which made my car not start or idle and stuck at 5v for a 100tps scale. I Started looking for a q45 sensor and did not want to pay the 130$ for a new one from a parts store when I can get the whole q45 tb and tps for that on the classifieds/eBay . I noticed that 90-97 Nissan 300zx comes with what appeared to be the same tps sensor. Therefore, I got a used one off a 300zx site for 20 bucks shipped. TwinTurbo.NET: Nissan 300ZX forum

When I got it and wired it up, I noticed that the sensors worked in opposite directions.(when I was at 100% throttle the tps would read 0% and 0V) I take it the 300zx tb shaft moves in a different direction than the q45 tb shaft. So all I did was wire the red and black wire opposite of what you would do for a q45 sensor. The white wire stays the same. I then set the tps scale in link and made sure the idle switch was working and bam, good to go. The 300zx sensor is made a little different inside and looks to be a more modern design. I just figured I would share for people who had a similar problem and a cheap solution because people will not sell just a q45 tps but they go for cheap on z32 sites.

 

[Blurred Talon]

Anyone have issues connecting the DSM throttle cable to the Q45 TB?
It's like the end of my cable is too big to fit into the TB.

 

[pneumo]

Anyone have issues connecting the DSM throttle cable to the Q45 TB?
It's like the end of my cable is too big to fit into the TB.

Yes, drill it bigger.

 

[Blurred Talon]

Thanks!